32kb cluster vs 64 on flash format? Ps3

[melodicmizery]

i got another new 2 tb drive to sort my movies and tv shows i play on my ps3s and ive always been confused about what cluster size to pick when formatting. i went back and looked at my other 2 2tb flash drives i use for my ps3 and it seems i have them at 64kb. for years this has worked. but while researching this morning i found tons of forums that said the max for ps3 was 32kb, yet 64kb still works for me. 

any rhyme or reason why people said 32? 

ive read for larger files like movies youll prob want a bigger kb size. was there a firmware update at some ppoint that upped the max from 32 to 64 or did it just never matter?